Related Field
The present invention relates to a method and apparatus for forming a three-dimensional article according to the set of claims presented herewith.
Description of Related Art
Freeform fabrication or additive manufacturing is a method for forming three-dimensional articles through successive fusion of chosen parts of powder layers applied to a worktable. A method and apparatus according to this technique is disclosed in US 2009/0152771.
Such an apparatus may comprise a work table on which said three-dimensional article is to be formed, a powder dispenser, arranged to lay down a thin layer of powder on the work table for the formation of a powder bed, a ray gun for delivering energy to the powder whereby fusion of the powder takes place, elements for control of the ray given off by the ray gun over said powder bed for the formation of a cross section of said three-dimensional article through fusion of parts of said powder bed, and a controlling computer, in which information is stored concerning consecutive cross sections of the three-dimensional article. A three-dimensional article is formed through consecutive fusions of consecutively formed cross sections of powder layers, successively laid down by the powder dispenser.
There is a need for a method and apparatus which enables manufacturing of larger 3-dimensional articles. However, with the existing technology as discussed above, larger articles require larger deflection of the energy beam, and at a certain size of the 3-dimensional article a maximum deflection may be reached. Surpassing the maximum deflection of the energy beam may affect the quality of the energy beam and capability of heating and/or fusing the powder material.